Development of Conductive Ceramic Composites by Preceramic Polymer

The formation, microstructure and electrical property of conductive ceramic composites derived from polymer pyrolysis were investigated. Methylpolysiloxane was mixed with TiH2 as a filler and pyrolyzed in nitrogen, argon and vacuum atmosphere at a temperature of 1600oC for 1 hour after the preheat treatment at 850oC in N2 atmosphere. Depending on the atmosphere conditions, TiN and Ti5Si3 phases were formed by reaction of TiH2 as reactive filler and atmospheric gas or pyrolytic product such as SiO2. Consequently, the microstructures of the ceramic composites with 70 vol.%TiH2 pyrolyzed at 1600oC for 1 hour in vacuum were composed of TiN and Ti5Si3 particles. The density and electrical conductivity of the ceramic composites were 97.3 TD% and 6200 ohm-1⋅cm-1, respectively. These composites pyrolyzed by polymer were considered as superior conductive material with a value of 103 ~ 104 in log scale at room temperature.